These multi-faceted otophysiology and otopathology research center efforts are conducted by a team of investigators who have worked together for several years. The Center focuses upon audiology, human auditory and vestibular function, animal auditory and vestibular function, morphology (both light and electron microscopy), and cellular biology--biochemistry as they relate to the pathophysiology of disorders of the senses of hearing and equilibrium. Specifically, the objectives are: (1) to develop and refine techniques for assessment of auditory disorders in children with particular emphasis on the acoustic reflex, brain stem evoked response, and behavioral correlates of central auditory disorders; (2) to study the human auditory nerve action potential and brain stem evoked response in order to further our knowledge of peripheral auditory physiology and to develop electrophysiologic tests that will quantify and localize hearing loss; (3) to investigate systematically alternative caloric irrigation test techniques in an effort to improve the clinical practicability of this vestibulometric test procedure; (4) to evaluate the functional alterations after partial ablation of the vestibular system and the system's subsequent compensation--both direct measurements (EMG analysis) and indirect measurements (degree of gait deviation) are used; (5) to investigate the inter-species generality of experimental evidence obtained in recent years regarding the role of the auditory neocortex in normal binaural hearing; and (6) to assess morphological and cell biology-biochemical findings as they relate to functional abnormalities.